This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Thiazolidinediones (TZD) are relatively new class of insulin-sensitizing agents used to treat type 2 diabetes mellitus (T2DM);however, 30-40% of subjects do not respond to TZD therapy. We hypothesize that variation in the genes encoding for PPARG2 or genes involved in the metabolism of TZDs may mediate response to TZDs. We propse a three month open-label piolitazone (PIO) trial in Latinas with previous gestational diabetes (GDM) to assess genetic association between candidate genes and response to pioglitazone.